Unusual presentation of JAK2-negative polycythemia

Abstract

Polycythemia vera is a relatively rare disease occurring in 0.02–2.8 per million population. Globally, about 95% of PV is due
to JAK2V617F mutation in the chromosome 9p. The remaining 5% were found to have a wide range of mutations including
JAK2 exon12 mutation and calreticulin (CALR) mutation. In India, the incidence of JAK2-negative polycythemia is relatively
high, reaching up to 18%. Polycythemia usually presents as symptoms secondary to hyperviscosity or as symptoms secondary to
increased histamine release by the cells. Herein, we describe a 46-year-old Indian male presented with a headache and found to be
in hypertensive urgency, which was later found to be secondary to JAK2-negative polycythemia.